Sometimes doesn't start

[Laith]

When I turn the key occasionally it decides not to start. Nothing, not even a noise from anything including starter motor. Eventually with enough turns of the key though it will start and when it does it it's absolutely fine.

I'm thinking it's electrical.. Anyone had this and solved it before?

[Brianmoooore]

Auto or manual? Model and age? My crystal ball's in for servicing as well!

[Laith]

Haha sorry! E30 320 manual 1992 cabrio. Could be the starter motor on your crystal ball too!

[Brianmoooore]

It's probably the actual switch at the back of the key barrel, but it's worth checking that the plug and socket where the black wire from the switch joins the black/yellow wire of the loom is pushed fully together. You'll find this plug and socket behind the panel above the driver's knees, and should be clipped to the steering column.
The next time it fails to turn over, open the bonnet and link the two pins on the diagnostic circuit to operate the motor, which will narrow down the location of the fault a bit.

[votivequagmire]

Are the lights going dim when you turn the key to the start position? If not then it sounds like a problem with the switch connected to the ignition. Remove the steering cowling and disconnect the plastic switch from the end of the ignition barrel and manually turn the switch a few times to check if it's operating correctly.

[Grrrmachine]

Just to echo Brian's suggestions, this is how to swing the motor over from the Diagnostic Plug:

http://www.e30zone.net/e30zonewiki/inde ... Plug_Start

[Laith]

Not going dim at all. Will try that. If the switch is dodgy is it replaceable?

[votivequagmire]

Yes and quite easily.
Item 3 om the following is the part you can see how it's attached when you see it. Trace the cable back to it's connectors. It may even have dislodged slightly.

http://www.realoem.com/bmw/showparts.do ... g=32&fg=30

And it looks something like this :